Funds are requested to upgrade a 10 year old GE Omega 500 NMR spectrometer. The upgraded instrument will provide modern triple resonance pulsed field gradient probes and RF electronics capability for the observation of macromolecules in solution. The proposed system will complement a modern 600 MHz instrument that is currently over saturated with users. The proposal includes 15 protein based projects from a total of eight NIH-funded investigators at the University of Oregon. The projects vary from detailed solution structure determination, investigations of the dynamic properties of folded proteins, folding mechanisms and thermodynamics, studies of protein-protein interaction, and investigations of catalytic mechanisms. These include the structure and dynamics of protein-protein interactions in bacterial signal transduction pathways, the structure of wild-type and mutant subunits of the F1F0 ATP synthase, the mechanism of DNA recognition by an unusual DNA binding motif found in the putative transcription factor, Skn-1, from C. elegans, the folding pathway of T4 lysozyme, solvent access into the hydrophobic cores and cavities of both T4 lysozyme and green fluorescent protein, the structure and function of a bacterial phospholipase C and the structural changes associated with mutations of the pro-sequence of yeast carboxypeptidase.